1. Field of the Invention
This invention pertains in general to computer networks and in particular to a broadband network for coupling end-users to Internet service providers.
2. Background Art
In recent years, there has been substantial growth in broadband Internet access. In the traditional sense, “broadband” refers to a transmission medium capable of supporting a wide range of frequencies. In more common parlance, however, “broadband” refers to a transmission medium capable of supporting a high data transfer rate. An example of a broadband network is a cable modem network.
In a broadband network, the network infrastructure closest to the end-user is referred to as the “customer access network.” The customer access network for a cable modem network is the cable that runs from a cable modem termination server (CMTS) in a cable television headend to the end-user and the radio frequency (RF) plant for driving the signals carried on the cable. Usually, multiple end-users share the bandwidth available on a single cable.
A customer access network is typically aggregated with other customer access networks and linked to a high-speed network backbone. The backbone, in turn, is linked to the Internet. Typically, the customer access network and backbone are owned and/or operated by a single entity, or by two entities operating under a joint agreement. For example, a cable network is typically owned by a single cable company called a Multiple Systems Operator (MSO) and the backbone is managed by a partner of the MSO.
While there are relatively few entities that own the broadband network infrastructure, there are many Internet service providers (ISPs) that desire to provide Internet access to the end-users. However, the entities that own the broadband network infrastructure have been reluctant to share network access with other ISPs due, in part, to the difficulty in sharing the bandwidth on the cable network. Bandwidth on the customer access network, while broadband, is not unlimited, and heavy use by the end-users of one ISP can impact the bandwidth available to the users of other ISPs. In one attempted solution to this problem, each ISP is allocated a 1.5 MHz upstream slice and a 6 MHz downstream slice of the available frequency spectrum. These slices are referred to as “channels.” In this solution, traffic for one ISP would not interfere with traffic for another ISP. However, the upstream frequency spectrum on a cable network available to cable modems is limited to frequencies below 80 MHz. Since this is a noisy part of the spectrum, there are usually only about six to 18 upstream channels available on the cable. It is inefficient and impractical to allocate channels to particular ISPs since ISPs with many end-users would require more bandwidth than is available in a channel while the channels of ISPs having few end-users would be underutilized.
Accordingly, the entities that own and/or operate the network infrastructure often require the end-user to use a single ISP. That ISP, in turn, is usually associated with the entity or entities that own and/or operate the network. Thus, an end-user with a cable modem typically uses an ISP affiliated with the MSO. If the end-user desires to use a different ISP, the end-user often must use a narrowband connection, such as an analog modem using a plain old telephone service (POTS) line, to connect to the ISP.
Since multiple ISPs desire access to the broadband network infrastructure, there is a need in the art for a way for the ISPs to efficiently share the available bandwidth on the customer access network and broadband network. A solution to this need should allow an end-user on a broadband customer access network to select from among multiple ISPs and should allow accounting for the bandwidth utilized by the customers of each ISP.